As Electric Boat’s workforce continues to grow, recently reaching 15,000 employees, a new report from the Congressional Budget Office points to the strain that could be placed on the submarine builder and others in the shipbuilding industry to meet the Navy’s new goal of 355 ships.

Late last year, the Navy unveiled a new force structure assessment that calls for 80 more ships, including 18 more attack submarines than it has now. President Donald Trump has called for a 350-ship Navy.

The CBO report says getting to 355 ships would cost, on average, $26.6 billion a year over the next 30 years. That’s more than 60 percent above the average amount that Congress has appropriated for shipbuilding over the past 30 years, the report points out.

Released last week, the report came at the request of U.S. Rep. Joe Courtney, D-2nd District, and U.S. Rep. Rob Wittman, R-Virginia, who respectively serve as ranking member and chairman of a House subcommittee with oversight over Navy shipbuilding.

Building more submarines would pose the greatest challenge to the shipbuilding industry, the report says. Hiring more workers and training new employees while maintaining current levels of quality and efficiency would present the most significant challenge industrywide, it added.

The Navy currently purchases two Virginia-class attack submarines a year, which EB and Newport News Shipbuilding in Virginia build under a teaming agreement, with each company alternating delivery of the submarines to the Navy. The report looks at a number of alternatives showing how the Navy’s new goal for 66 attack submarines could be met.

Of the four alternatives examined, reaching the Navy’s goal in 15 years would pose the most difficulties. That would mean building three attack submarines per year from 2022 through 2024, and four from 2025 through 2028.

EB President Jeff Geiger said in January, following the release of the Navy’s assessment, that his company is poised to meet the Navy’s demand for 66 attack submarines, provided it has the time to build up its workforce, supplier base and facilities.

Several training programs have been established around the region in the past two years, many at technical high schools and community colleges, to help train prospective workers for EB. Last month, The Day reported that the company expects to hire 2,000 employees this year alone.

Construction on the first submarine in a new class of ballistic missile submarines, known as the Columbia class, is expected to begin in 2021. EB is the prime contractor for that program, and thus will carry out most of the work on the Columbia boats, which will be two-and-a-half times larger than the Virginia-class attack submarines. Twelve of these Columbia submarines are planned.

Even before the Navy released its latest assessment, EB was planning for more work. It had set a goal of reaching 18,000 employees by 2030. The company also is preparing to spend $1.5 billion to expand its facilities in Groton and Quonset Point, R.I. In Groton, the company would like to build a new floating dry dock on the south end of its campus to be able to deliver the Columbia submarines.